Racking mechanism for draw-out type miniature high voltage circuit breaker

ABSTRACT

Miniaturized modular high voltage truck mounted switchgear in which circuit interrupter elements on a frame are movable with respect to a truck frame and the truck frame is itself removably mounted in a cubicle in a switchboard. The circuit interrupter elements may then be racked into a connected position with respect to busses in the switchboard and may also be racked out. The circuit interrupter elements, when racked out, telescope with the operating elements of the truck mounted frame; the connection between the operating elements of the truck mounted frame and the circuit interrupter elements includes a link which is pivotally mounted on a driving member carried by the truck and hingedly connected to the circuit breaker elements. This link may swing into the region of the operating members mounted on the truck and may swing away therefrom, to permit the telescoping of the frame which carries the circuit interrupter elements into the truck frame. Racking mechanism is provided which will move the frame carrying the circuit interrupter elements with respect to the truck. The racking mechanism may be motor driven or manually driven and is mounted on the truck frame. Interlocks are provided between the truck frame and the cubicle in the switchboard not only to anchor the truck frame in the switchboard but to ensure that racking out will occur only under an open condition of the interrupter breakers and that auxiliary contacts will be disengaged before any removal of the truck.

Jan. 8, 1974 1 RACKING MECHANISM FOR DRAW-OUT TYPE MINIATURE HIGH VOLTAGE CIRCUIT BREAKER [75] Inventor: George A. Wilson, Pineville, Pa.

[73] Assignee: I-T-E ImperialCorporation,

Philadelphia, Pa.

221 Filed: Aug. 21, 1972 [21] Appl. No.: 282,319

us. (:1 2 00/50 AA,200/l53 sc Primary Examiner.1. R. Scott Attorney-Ostrolenk, Faber, Gerb & Soffen [57] ABSTRACT Miniaturized modular high voltage truck mounted switchgear in which circuit interrupter elements on a frame are movable with respect to a truck frame and the truck frame is itself removably mounted in a'cubicle in aswitchboard. The circuit interrupter elements may then be racked into a connected position with respect to busses in the switchboard and may also be racked out-The circuit interrupter elements, when racked out, telescope with the operating elements of the truck mounted frame; the connection between the operating elements of the truck mounted frame and the circuit interrupter elements includes a link which is pivotally mounted on a driving member carried by the truck and hingedly connected to the circuit breaker elements. This link may swing into the region of the operating members mounted on the truck and may swing away therefrom, to permit the telescoping of the frame which carries the circuit interrupter elements into the truck frame. Racking mechanism is provided which will move the frame carrying the circuit interrupter elementswith respect to the truck. The racking mechanism may be motor driven or manually driven and is mounted on the truck frame. Interlocks are provided between the truck frame and the cubicle in the switchboard not only to anchor the truck framein the switchboard but to ensure that racking out will occur only under an open condition of the interrupter breakers and that auxiliary contacts will be disengaged before any removal of the truck.

23 Claims, 44 Drawing Figures PATENTEM 3.784.764

sum new 1 PATENTEU JAN B1974 SHEET 03M 21 7 WJ/ \u H H n An m Maw: WW 2 r g 2 w WK WW 6/ 5L w M w 6 2 \b# :2 an [m Z2 7 L2 WK M W W? J mm m 2 rm 5 p/ 0/ r/ a 2 PAIENTEUJAN 81974 3.784164 sum [MP 1 5 2: 4 Mar 5/wF' PAIENTEU JAN 8 I974 sum 05 0F 21 PAIENIEDJAN 8W4 75 sum USUF 21 PATENTEDJAN. 8%974 3,784,764

sum 110F21 mq I hN PATENTED JAN 8 I974 saw '12 us 1 PAIENTEDJAN 8W 3.784.784

sum 1n or 21 PATENTED 74 3784764 saw 15M 21 PATENTED JAN 8 I974 sum 15 or 21 m N E PATENIEU JAN 8 I974 sum 15 or 21 QNR 

1. Miniature high voltage switchgear comprising: a first frame, switchgear operating and control members carried by said first frame, a second frame reciprocally mounted with respect to said first frame, switchgear members carried by said second frame, said switchgear members including at least two separable contacts, at least a pair of back connection studs carried by said second frame, one of said pair of contacts being connected to one of said pair of back connection studs and the other of said pair of contacts being connected to the other of said pair of back connection studs, contact operating members on said second frame for moving said contacts toward and away from each other. an operating and control link, a pivotal connection for said operating and control link to the switchgear operating and control members carried by said first frame, an end of said operating and control link remote from said pivotal connection being connected to the said contact operating means, the line between the first mentioned pivotal connection of said link to said switchgear operating and contact members and the connection of said link to said contact operating means being substantially normal to the path of reciprocal movement of said second frame, said link swinging into the area of said first frame and its switchgear operating and control elements on movement of said second frame in a first direction with respect to said first frame to a withdrawn position of the second frame, and away from the area of said first frame and its switchgear operating and control elements on movement of said second frame in an opposite direction with respect to said first frame to an inserted position of the second frame.
 2. The miniature high voltage switchgear of claim 1 in which: said second frame carries an evacuated housing, said switchgear contacts being located and operable in said evacuated housing; one of said contacts being a movable contact; a rod extending from said housing connected to said movable contact and being longitudinally movable to drive said movable contact toward and away from the other contact, an opening spring biasing said rod to movement in a direction to drive said separable contact away from said other contact, said operating members on said second frame including a connection to said rod, the position of said rod and the position of the movable contact being under the control of said switchgear operating and control means on said first frame acting through said operating and control link on said contact operating members.
 3. The miniature high voltage switchgear of claim 2 in which the said operating and control link controls the operating members on the second frame in the fully inserted and fully withdrawn position of the second frame.
 4. The miniature high voltage switchgear of claim 2 in which said switchgear operating and control members include a closing spring and a connection between said closing spring and said operating and control link; means for charging said closing spring and means for retaining said closing spring in charged condition, first latch means retaining said closing spring in charged condition; said first latch means being operable to release the charged closing spring to permit the same to drive the said operating and control link in a direction to act through the said contact operating members to drive the rod and movable contact against the bias of said opening spring in a direction to engage the movable contact with its other contact; and a second latch, a connection between the second latch and the operating and control link maintaining said link in position to drive and retain said movable contact in engaged position; said second latch being trip free and releasable to permit the said opening spring to drive the said rod, its movable contact and operating and control link to disengage the movable contact from its contact in the charged position of the closing spring, and driving the closing spring to the discharged position of the closing spring.
 5. The miniature high voltage switchgear of claim 4 wherein said closing spring may be charged and discharged while the movable contact is retained in the engaged position with its complementary contact by the said second latch and said operating and control link, and while the movable contact is permitted to be operated to disengaged position by the opening spring on operation of said second latch and of the operating and control link to release the said opening spring.
 6. The miniature high voltage switchgear of claim 1 in which: on such movement of said second frame in said first direction, at least certain of said contact operating elements move into the area defined by said first frame and the switchgear operating and control elements carried thereby.
 7. The minature high voltage switchgear of claim 6 in which: the said contact operating elements enter into the section of the switchgear containing said switchgear operating and control elements in the area defined by said first frame, on completion of said movement in said first direction.
 8. The miniature high voltage circuit breaker of claim 7 in which: said second frame and the members carried thereby may be removed, replaced and substituted by disconnecting and reconnecting said end of said operating link remote from said pivotal connection with the switchgear operating and contact member.
 9. The miniature high voltage circuit breaker of claim 7 in which: the connection between said end of the operating and control link remote from said pivotal connection with the switchgear operating and control members and said contact operating members constitutes the only connection between said contact operating members and said switch gear operating and control members.
 10. The miniature high voltage switchgear of claim 9 in which said connection comprises a link, said link having a first position when the circuit breaker is racked in and a second position when the circuit breaker is racked out; said first and second position being symmetrical about a vertical axis.
 11. The miniature high voltage switchgear of claim 7 in which: said back connection studs are parallel to each other; said back connection studs extending parallel to the path of reciprocal movement of said second flame; a housing for said switchgear, said housing having a rear wall normal to the path fo reciprocal movement of said second frame; connectors in said rear wall for cooperating with said back connection studs; said back connection studs engaging said connectors on completion of said movement of said second frame in said opposite direction, said back connection studs disengaging said connectors on initiation of movement of said second frame in said first direction, said back connection studs approaching the said switchgear operating and control means as the contact operating members on the second frame enter into the area of the switchgear having said switchgear operating and control members on the first frame.
 12. The miniature high voltage circuit breaker of claim 11 in which: interlock means are provided between said first frame and said housing; said interlock comprising a rotatable hook member carried by said first frame and a stationary member carried by a wall of said housing; said hook and stationary member being interengageable when said first frame is contained within said housing, means interconnecting said hook and the said switchgear operating and control members carried by said first frame, said hook being locked into engagement with said stationary member when said switchgear racking mechanism and control back disconnect contacts are in any position other than the disconnected position.
 13. The miniature high voltage switchgear of claim 11 in which: a plurality of stationary secondary contacts are provided in the housing; corresponding movable secondary contacts; said corresponding movable secondary contacts being carried by said first frame, said movable secondary contacts being movable into engagement with said stationary secondary contacts when said switchgear is fully inserted in said housing, and means for locking said secondary contacts in engagement when said second frame is in fully inserted position and the back connection studs are engaged with their respective contacts.
 14. The miniature high voltage circuit breaker of claim 11 in which: said connectors are recessed in said rear wall; a shutter is mounted on said rear wall; said shutter being movable to a position blocking access to said connectors on disengagement of said back connection studs from said connectors; said shutter being movable to unblock the said connectors on initiation of movement of said second frame in said opposite direction.
 15. The miniature high voltage circuit breaker of claim 14 in which: at least one of said connectors is connected to a source of current at high voltage and on completion of movement of said second frame in said first direction, the entering of the contact operating members into the arc of the said switchgear operating and control members, the close approach of the contacts to the said switchgear operating and control members and the movement of said shutter to block access to the connectors, the entire miniature high voltage circuit breaker is isolated from said connectors and the switchgear operating and control means may be operated safely.
 16. The miniature high voltage circuit breaker of claim 11 in which: a racking mechanism is provided, said racking mechanism being mounted on said first frame and having a rotatable element, and means for rotating said rotatable element in two directions, a connection between said rotatable element and said second frame, said racking mechanism effecting said reciprocal movement of said second frame with respect to said first frame; said rotatable element, on rotation thereof in a first direction causing said second frame to move in said first direction; said rotatable element, on rotation thereof in an opposite direction causing said second frame to move in said opposite direction.
 17. The miniature high voltage switchgear of claim 16 in which a plurality of stationary secondary contacts are provided in the housing; Corresponding movable secondary contacts; said corresponding movable secondary contacts being carried by said first frame. said movable secondary contacts being movable into engagement with said stationary secondary contacts when said switchgear is fully inserted in said housing, and means for locking said secondary contacts in engagement when said second frame is in fully inserted position and the back connection studs are engaged with their respective contacts, and a connection between said racking mechanism and said movable secondary contacts locking said movable secondary contacts into engagement when said frame is fully inserted in said housing.
 18. The miniature high voltage switchgear of claim 17 in which: said last mentioned connection is movable to release and unlock selected said movable secondary contacts when said second frame is in a fully withdrawn position with respect to said first frame.
 19. The miniature high voltage switchgear of claim 18 having a further connection between the switchgear control members on said second frame and said movable secondary contacts said connection unlocking all of the secondary contacts when the second frame is in a fully withdrawn position with respect to the first frame.
 20. The miniature high voltage switchgear of claim 16 in which: interlock means are provided between said first frame and said housing; said interlock comprising a rotatable hook member carried by said first frame, and a stationary member carried by a wall of said housing; said hook and stationary member being interengageable with the said first frame is fully inserted within said housing, means interconnecting said hook and said racking mechanism, said hook being locked into engagement with said stationary member when said racking member has operated said second frame to any position away from the fully withdrawn position of the second frame and the back disconnect contacts have moved to any position other than the fully withdrawn position with respect to the wall-mounted contacts.
 21. The miniature high voltage switchgear of claim 20 in which additional means are provided interconnecting said hook and the switchgear operating and control members carried by said first frame, and hook being locked into engagement with said stationary member when said switchgear operating and control members are in any position other than the disconnect position of the back disconnect contacts.
 22. The miniature high voltage switchgear of claim 21 in which: the switchgear including the first and second frame being fully withdrawable from the housing when the second frame has completed its movement in said first direction and the hook is rotatable out of engagement with said stationary member; said switchgear being insertable into said housing, said hook being rotatable to engage said stationary member when said second frame is in the fully withdrawn position with respect to said first frame and the back disconnect contacts are fully withdrawn from the wall mounted contacts. said hook being blocked from rotation and the end of the hook abutting the said stationary member and blocking insertion of the switchbear into the housing when the second frame is in any position away from the fully withdrawn position on the first frame.
 23. The miniature high voltage switchgear of claim 22 in which: a plurality of stationary secondary contacts are provided in the housing; corresponding movable secondary contacts; said corresponding movable secondary contacts being carried by the first frame; said movable secondary contacts being movable into engagement with said stationary secondary contacts when said switchgear is fully inserted in said housing, and means for locking said secondary contacts in engagement when said second frame is in fully inserted position and the back connection studs are engaged with their respective wall mounted contacts, and a connection between saiD racking mechanism and said movable secondary contacts; said connection locking said movable secondary contacts into engagement when said second frame is fully inserted in said housing, said connection being movable to release and unlock selected secondary contacts when the second frame is in a fully withdrawn position with respect to said first frame, said hook also blocking entry of said switchgear into said housing when said movable secondary contacts are in any position other than a fully disconnected position. 